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Prescriptions, Perfectly Personalized

Nursing professor Jay Tan uses pharmacogenetics to unlock the medications and dosages that work for a patient's individual genetic makeup.

Research  |  Jul 11, 2017  |  By Matt Jacob
Nursing professor Jay Tan

Nursing professor Jay Tan gathers genetic material with a cheek swab. The simple test can help physcians customize their prescriptions to a patient's genetic makeup. (R. Marsh Starks/UNLV Creative Services)

It’s just past noon on a sweltering midweek day, and assistant professor Jay Tan has wrapped up a four-hour lecture for one of his summer nursing courses. Sitting in his fourth-floor office of the Bigelow Health Sciences building, he shares a story about a patient he helped as a nurse practitioner specializing in mental health.

The woman had tried multiple medications, none of which relieved her psychosis symptoms, which included seeing and hearing things that weren’t real. Tan suggested using genetic testing to better understand how her body reacts to medication. That led to a change in her prescriptions. Her symptoms gradually improved and within six months, Tan says, his patient felt so good that she rejoined the workforce.

“Suddenly during one of our visits, she became tearful,” he recalls. “She looked at me and said, ‘Dr. Tan, like you, my mom was a nurse practitioner, and like me, she had [mental health problems]. She committed suicide. And in her notes, she wrote, ‘Nothing works.’”


Tan has turned to pharmacogenetics to help his patients find what will work before they give up. Pharmacogenetics is the science of how our genetic makeup affects the way in which our bodies absorb and react to different medications.

“Over time, medication has come to be viewed as a solution for certain health problems,” he said. “But not all medications work the same way in all patients.”

Typically, pharmaceuticals have been dispensed through a trial-and-error method — a method that can be expensive and exhausting if the medication doesn’t hit the bull’s-eye on the first, or second, or third try. Pharmacogenetics aims to make the target much easier to hit using a genetic test to identify what medications are most likely to work, and which to avoid.

What’s more, these genetic tests can also help physicians more accurately refine a patient’s dosage than the standard practice of dosing by weight, seeing how patients respond, and then adjusting.

“Take the anti-depressant Prozac,” Tan says. “The book says to start adults with 20 milligrams. But if we know, after looking at your genes, that you’re an ultra-rapid metabolizer, we’ll know that 20 milligrams isn’t enough—it won’t do anything for you, so I should probably start you at 40 milligrams.

“The opposite is also true: If you’re a poor metabolizer, 20 milligrams is too much because the body will hold [the chemicals] for too long,” he said, noting that the side effects may also be greater.

Think of pharmacogenetics as killing two scientific birds with one stone: By receiving the appropriate type and amount of medication from the jump, patients see their symptoms mitigated sooner. When that happens, they are more likely to remain on their medications rather than abandon them in frustration — a common problem among those with mental health disorders.

Pharmacogenetics has been gaining acceptance in the medical industry, Tan says, citing a recent survey in Clinical Pharmacology & Therapuetics that indicated 97 percent of physicians believe pharmacogenetics can have a “positive impact on the delivery of health care.” However, only 12 percent of those surveyed have incorporated pharmacogenetics as part of their treatment procedures.

Tan says there are two reasons for this: One is cost (the health insurance industry hasn’t been quick embrace pharmacogenetics); the other is a lack of physician knowledge/training (the field is so new that it has not been incorporated into the curricula for most medical professionals).

Tan remains hopeful that, with time and continued research like he is currently conducting, both of those hurdles will one day be cleared. Because he’s witnessed firsthand how pharmacogenetics can vastly — and quickly — improve the quality of life for mental health patients. That patient whose mother committed suicide had contemplated the same herself until they found an effective medication.

The way Tan views it, such success stories prove that pharmacogenetics can go a long way toward eliminating societal stereotypes about mental health — stereotypes that often keep those dealing with mental disorders from coming forward and asking for professional assistance.

“A lot of people with mental health problems still don’t want to seek help because of social stigma,” Tan says. “But look at diabetes: It’s a chemical imbalance brought about by genetics. Yet diabetics who receive insulin aren’t ostracized in the community.

“But if you’re depressed, suicidal, manic depressive — which are all the result of a chemical imbalance — when you talk about it or seek treatment, people often say, ‘Really? Are you that bad?’ And there’s the stigma.

"Now I have scientific, biological data that proves mental illness is not a wrath from God. It’s not a sign of weakness.”


Tan’s career seems to be a nonstop cycle of learning, caring, and teaching. That passion for learning and teaching filtered down from his mother, who was an educator in their native Philippines.

Growing up, Tan was drawn to medicine and the sciences, fascinated by all things related to anatomy, physiology, theories, and genes. He focused on nursing, attending Cebu State Medical Center College of Nursing (now known as Cebu Normal University), and graduated first in his class in 1990.

Four years of clinical nursing work and a master’s degree later, Tan left his homeland and for a job at a long-term care nursing home and rehabilitation facility in North Las Vegas. Tan took advantage of the Nursing Relief Act of 1989, in which immigrant nurses who passed an international examination were granted visas to work in the U.S., which was suffering from a nursing shortage. He has since added another master’s degree and a doctorate to his credentials.

Tan joined the UNLV School of Nursing faculty during 2005. During his lectures, he emphasizes the importance of nurses doubling as educators and is also ensuring they understand the virtues of genetic testing, which is being integrated into the curriculum.

“My goal,” he says, “is to not make my students scientists, but to produce nurses who are informed and knowledgeable about genetic testing and the positive impact it can have on all patients.”